The present invention relates to a bearing assembly construction, and more particularly to a bearing assembly construction suitable for assembling a rolling bearing of hard metal within an axle box structure of soft metal such as aluminum alloy.
In case a rolling bearing of steel metal directly assembled within an axle box structure of aluminum alloy is used in a high temperature atmosphere, an undesirable clearance occurs between the axle box structure and the rolling bearing due to a difference between respective coefficients of thermal expansion of the two metals. The clearance causes relative rotation of the outer race of the bearing against the axle box structure, causing defacement of the structure. To avoid the above-noted defects, it has been proposed that a sleeve member of hard metal be secured by a press fit or shrink fit in position within the axle box structure to fixedly assemble the rolling bearing. In such a conventional bearing construction, it is required that the press fit or shrink fit of the sleeve member be made in consideration with such various conditions as temperature in use, strength of the axle box structure, rotational speed of the axle and the like to ensure the accuracy of the bearing assembly without undesirable displacement of the sleeve member in replacement of the bearing. This results in various difficulties in actual practices of the bearing assembly construction.